"Face smooth. Palpi long, straight, porrected, shortly rough-scaled, terminal joint short. Antennæ in male simple, stout, gradually dilated from base to near apex, apex attenuated. Abdomen in male very excessively elongate. Hind-wings in male deeply excised near dorsum, dorsal lobe folded into a long pocket, fringed with hairs. Fore-wings with vein 6 rising out of 9, 7 from or above angle of areole, 10 anastomosing moderately with 9, 11 anastomosing moderately with 10, 12 free. Hind-wings with veins 6 and 7 separate, 8 free, united with 7 before transverse vein by an oblique bar. "This singular genus is a remnant of a widely diffused, but now fragmentary group, to which belong also _Lobophora_ (Europe), _Rhopalodes_ (South America), _Sauris_ (Ceylon), and _Remodes_ (Borneo.) In all, the hind-wings of the male are peculiarly modified, usually much diminished in size, and with the dorsum formed into a distinct lobe, the object of which is unknown. A similar structure is found only in one or two genera of _Tortricina_. _Rhopalodes_ is the nearest genus to this, but vein 5 is said to be obsolete, and the lobe does not form a pocket; in _Sauris_ the areole is simple, and the antennæ thickly scaled; in _Remodes_ the areole is also simple, the antennæ flattened and scaled, and the dorsum is furnished with three superposed lobular folds, so that it represents the extreme of development in this direction."--(Meyrick.) It will be seen on reference to Plate II., figs. 22 and 23, which represent the structure of the hind-wings of the male and female of _Tatosoma agrionata_ respectively, that in the male veins 1 and 2 are absent, having no doubt become absorbed during the formation of the characteristic sexual lobe; vein 8 is connected with the margin of the cell by an oblique bar, this being probably due to an extension of the wing in the costal region, compensating for the loss in the dorsal region due to the above-mentioned lobe. In the hind-wings of the female the normal neuration of the family is almost preserved, the only peculiar feature consisting in the origin of veins 6 and 7 from a point on the margin of the cell. Of this remarkable genus we have three species, and I think it quite possible that others may reward the industry of future collectors. TATOSOMA LESTEVATA, Walk. (_Cidaria lestevata_, Walk. 1416. _Sauris ranata_, Feld. cxxxi. 11., _Tatosoma lestevata_, Meyr., Trans. N. Z. Inst. xvi. 67.) (Plate VI., fig. 25 [M].) This beautiful species has occurred at Wainuiomata, near Wellington, in the North Island, and at Nelson and Christchurch, in the South Island.